WarMech

Oh yeah, he was a random encounter in the sky castle. Yep, the most powerful guy in the game was not the last guy (chaos). If you weren't looking for a warmech (a good way to get to the highest level in the game (50). He gives a crapload of XP and gold) he will most likely wipe out your party.

Story behind this guy: Supposedly one of the guardian robots who worked for the people of lefien and were left behind when they were kicked out of the sky castle by the 'bad people'.